Post-deployment screening suggests that approximately 10% of veterans returning from OIF endorse screening questions suggesting they have PTSD, and because of these symptoms, are at particularly high risk for alcohol and other substance use disorders. Fully half of all OEF/OIF veterans and a majority of those with PTSD are expected to apply for disability benefits. Claimants undergo the required VA Compensation examination to determine the nature and severity of their disability and ultimately, the amount they will be compensated. Veterans with PTSD symptoms who apply for Compensation benefits are at a crucial stage in their disease course because they are making far-reaching global decisions about whether to consider themselves disabled, what their diagnoses are, and whether to engage in treatment. The disability evaluation presents a perfectly-timed opportunity to evaluate veterans' concomitant substance abuse and offer treatment, but this opportunity is typically missed. There is also much speculation but little data concerning what factors determine which veterans with PTSD attend treatment and the relationship of this attendance to their Compensation claim. In the Evaluative Component of this study, a fixed-ratio sample of 640 OEF/OIF veterans undergoing PTSD disability evaluations will complete an assessment battery consisting of potential predictors of outcome: substance use, PTSD severity, attitudes concerning Compensation examinations and others. Approximately 160 veterans identified as having a Substance Use Disorder or risky alcohol use will then enter the Clinical Trial Component of the study, and will be randomly assigned to an intervention based on SAMHSA's SBIRT (Screening, Brief Intervention and Referral to Treatment) or No-Additional-Treatment. The primary clinical trial outcomes will be weeks attending any mental health and/or substance abuse treatment and days abstinent from illicit drugs and alcohol. All veterans, including those from the Evaluation Component, will be re-assessed four weeks and twelve weeks after the Compensation examination and VA service use data will be extracted through the period after a disability determination has been made. The effect of the predictors on veterans' substance use, PTSD severity, and attendance at mental health and/or substance abuse treatment will be determined for the time periods before applying for service connection, after applying, and after disability determination. The proposed studies will determine (i) the impact of substance abuse on outcomes and attendance at treatment; (ii) the impact of attitudes about the Compensation exam and other predictors on outcomes and attendance at treatment; and (iii) the efficacy of screening and referral to treatment, a treatment approach that has the potential to transform a widely-used point of contact with VA.